This invention relates to curable compositions of polyarylcyanate ester compositions and copolymerizable ethylenically unsaturated monomeric compositions, and to cured resins prepared from the compositions.
Thermoset resins are used in many engineering applications as fiber-reinforced plastics and composites, molded articles, coatings, adhesives and the like. It is desirable that such resins possess temperature and chemical resistance, and are readily processable in molding, extrusion, and hand lay-up processes.
The resins prepared from polyfunctional cyanate esters exhibit good temperature and chemical resistance properties. Such resins copolymerized with maleimide monomers are disclosed in U.S. Pat. Nos. 4,469,859; 4,404,330; 4,396,745; 4,383,903; 4,373,086; 4,371,689; 4,369,304; 4,287,014 and 4,110,364. To prepare the resins, separate prepolymer compositions of the cyanate ester, the maleimide, and other comonomer must first be prepared. Such a processing step substantially detracts from the processability and desirability of the resins.
Furthermore, the curable and prepolymer polyfunctional cyanate ester compositions are highly viscous. Such high viscosity inhibits the use of these compositions in applications which require low viscosity compositions. Examples of such applications are filament-wound pipe, electrical laminates, coatings, and structural composites.
Therefore, it would be desirable to have curable polyarylcyanate ester compositions which have improved processability. It would also be desirable that the improved processability would not detract from the physical properties of the cured compositions.